<template>
    <h1>Hello web</h1>
    count: {{count}}
    <button @click="incre">+1</button>
</template>
<style> 
    h1{color: red;}
</style>
<script setup>
import { ref,onMounted } from 'vue';
onMounted(()=>{
    console.log('count');
})
let incre = ()=>{
    count.value++;
}

let count = ref(0);// 声明一个响应式变量
count.value = 100;

</script>